1. Field
Example embodiments relate to a method of forming a gallium nitride (GaN) thin film with a relatively low defect density on a silicon substrate.
2. Description of the Related Art
Sapphire substrates are conventionally used for semiconductor light emitting devices. Gallium nitride (GaN) light emitting cells may be easily grown to a thickness of 5 μm or more on a sapphire substrate. However, a sapphire substrate is relatively expensive and more difficult to manufacture for larger diameters.
Light emitting devices may also have GaN light emitting cells grown on a silicon substrate. However, a relatively high number of cracks in the GaN light emitting cells may form as a result of differences in lattice constants and thermal expansion coefficients between the GaN light emitting cells and the silicon substrate. The number of cracks may increase with GaN layer thickness.
Furthermore, because the silicon substrate absorbs a portion of light emitted by the GaN light emitting cells, the amount of light actually emitted is reduced. To increase the amount of light emitted, an additional process of removing the silicon substrate from the GaN light emitting cells may be required.